Vehicles have been developed heretofore wherein the frame may be raised and lowered and wherein the spacing between wheels may be adjusted. Vehicles of this type have been used for material handling, as tool carriers, crop sprayers, and to apply fertilizers. For agricultural purposes such vehicles proceed along a row of crops with the wheels straddling the plants so as to pass between the rows. In the past a single vehicle had deficiencies with respect to the range of varying the clearance and wheel spacing and the larger vehicles have generally lacked durability. In general, prior known vehicles of this type have not been entirely satisfactory for all types of requirements.
High clearance vehicles such as those disclosed in U.S. Pat. Nos. 3,179,194, Hunt, 3,236,324, Levratto, and 3,964,565, Cagle et al., connect the frame directly to the wheel assemblies and by so doing limit the minimum clearance for the frame.
Clearance variations for a vehicle frame disclosed in U.S. Pat. No. 4,029,165, Miller et al., are provided by the use of a ram contained in telescoping cylinders with an outer cylinder connected directly to the frame and the inner cylinder connected to the top plate of a bogeymount for a steering motor.
Wheel spacing variations disclosed in U.S. Pat. Nos. 3,154,164, Shaw et al., and 3,236,324, Levratto, are provided by telescoping members supported by the frame and connected between laterally opposite wheels.
U.S. Pat. No. 4,029,165 discloses the use of a hydraulic cylinder for steering each wheel and U.S. Pat. No. 3,236,324 discloses linkage associated with a single hydraulic cylinder between the front and rear wheels.